One regex took Cloudflare offline
How a new firewall rule in simulate mode hit catastrophic backtracking, maxed out the CPUs serving web traffic across Cloudflare's whole network and caused 27 minutes of outage on 2 July 2019.
01 · A rule meant only to watch
WS · One line of regex knocked Cloudflare offline for 27 minutes
One rule, meant only to watch.
A rule meant only to watch
2 July 2019.
0:00 / 2:37